The present invention relates to an apparatus and method for generating an image which can be translucently displayed.
There are known various types of image generating systems which can be used in game devices, image generating tools and others. Such image generating systems have an technical subject relating to how to improve the quality of image for realizing a so-called virtual reality. One of such techniques improving the quality of image is a technique known as a translucence process.
The translucence process provides image information for every pixel as by blending color information for a translucent display object with color information for the background. By means of the translucence process, the translucent object can be displayed to provide an image further improved in reality.
However, the conventional translucence process will cause all the portions of an object to be subjected to translucence control, for example, when the object such as a polygon or sprite is translucently drawn. When an opaque portion exists within the object, therefore, the opaque portion will also be subjected to translucence control. Therefore, the portion that should always be remained as opaque must be treated as a separate object. This leads to enlargement of the hardware scale and to increase of the processing load.
To overcome the aforementioned technical problem, it is thus an object of the present invention to provide an image generating apparatus and method which can perform a high-quality translucence process with reduction of the hardware scale and processing load.
To this end, the present invention provides an image generating system for performing a translucence process, comprising:
translucence process means for performing translucence process based on first translucence information and second translucence information, the first translucence information carrying out a translucence control to each portion of an object and the second translucence information carrying out the translucence control to entire portion of the object, and
invalidation means for invalidating the translucence control according to at least the second translucence information with respect to a portion of the object that is judged to be opaque according to the first translucence information.
With the image generating apparatus of the present invention, the translucence process is executed based on the first and second translucence information. The first translucence information is used to perform the translucence control with respect to each portion of the object such as a polygon or sprite. The second translucence information is set for each object or scone (screen) and used to perform the translucence control with respect to entire portion of the object. The present invention invalidates the translucence control according to the second translucence information with respect to a portion to be opaque. At this time, the translucence control according to the first translucence information may be invalidated in addition to the translucence control according to the second translucence information. The invalidation of the translucence control may be carried out by various techniques such as a technique of varying the translucence information itself or a technique of omitting portion or all of the translucence process. The same object can simultaneously have a first portion left opaque by invalidating the translucence control according to the translucence information and a second portion normally subjected to the translucence control according to the first and second translucence information. More particularly, one object will not be divided into several objects such as a first object as the first portion and a second object as the second portion. The first portion left opaque irrespectively of the second translucence information and the second portion normally subjected to the translucence control can coexist on the same object. As a result, a high-quality translucent image can be obtained with small scale of hardware and less processing load.
As an aspect of the present invention, the translucence process means may also perform the translucence process based on third translucence information obtaining from the first and second translucence information, and the invalidation means may fix the third translucence information with respect to a portion of the object that is judged to be opaque according to the first translucence information irrespectively of the second translucence information.
With this aspect, the third translucence information is fixed with respect to the first portion that is judged to be opaque irrespectively of the second translucence information. Thus, the first portion can be opaqued without depending on the second translucence information. Particularly, the present invention can invalidate the translucence control according to the second translucence information through such a simple process of fixing the third translucence information. This can simplify the process and reduce the processing load.
As another aspect of the present invention, the translucence process means may perform first and second translucence processes according to the first and second translucence information respectively, and the invalidation means may invalidate at least the second translucence process with respect to a portion of the object that is judged to be opaque according to the first translucence information.
With this aspect, the second translucence process in the translucence process means is invalidated with respect to the first portion which is judged to be opaque. At this time, the first translucence process may be invalidated in addition to the second translucence process. The present invention can invalidate the translucence control according to the second translucence information through such a simple process of invalidating the translucence process. This can simplify the process and reduce the processing load.
As other aspect of the present invention, the object may be a polygon, the first translucence information may be used for performing the translucence control with respect to each part of the polygon, and the second translucence information may be used for carrying out the translucence control with respect to entire part of the polygon.
With this aspect, the same object can simultaneously have a portion being opaque irrespectively of the second translucence information and the second portion subjected to the translucence control according to the first and second translucence information,
As further aspect of the present invention, the first translucence information may have been stored in a given texture information storage means together with at least one of color information, brightness information, surface shape information, reflectance information, refractive index information and depth information.
With this aspect, the first translucence information has beer stored in the texture information storage means as one of the texture information together with the color information and others. By changing the first translucence information for each portion of the object on which the texture is mapped, the color as well as the translucence can be represented with different designs for the respective object portions.
As one of the information used for representing the design of the object, such a first translucence information is required in addition to the color information and others. On the other hand, when it is desired to vary the translucence in the entire object, there is required the second translucence information used to perform the translucence control with respect to the entire object. When such two kinds of the different translucence information are used, the following problem will be raised. That is, when a portion of the object is to be opaqued in design according to the first translucent information, that portion may become translucence under influence of the translucence control according to the second translucence information. The present invention can avoid such a problem since the translucence control according to the second translucence information is invalidated with respect to the portion which is judged to be opaque according to the first translucence information.
As yet further aspect of the present invention, a process of invalidating the translucence control according to the second translucence information with respect to a portion judged to be opaque may be switchable to a process of validating the translucence control.
With the aspect of the present invention, the translucence control according to the second translucence information with respect to an opaque portion of the object can either be invalidated or validated. In other words, the operating mode can be switched between a mode in which the opaque portion of the object is left opaque irrespectively of the second translucence information and another mode in which the portion becomes translucent under the translucence control according to the second translucence information. This enables an image to be represented with variety.